Pileus Git - ~andy/gtk/blob - gtk/gtkbin.c

   1 /* GTK - The GIMP Toolkit
   2  * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * Modified by the GTK+ Team and others 1997-2000.  See the AUTHORS
  20  * file for a list of people on the GTK+ Team.  See the ChangeLog
  21  * files for a list of changes.  These files are distributed with
  22  * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
  23  */
  24
  25 /**
  26  * SECTION:gtkbin
  27  * @Short_description: A container with just one child
  28  * @Title: GtkBin
  29  *
  30  * The #GtkBin widget is a container with just one child.
  31  * It is not very useful itself, but it is useful for deriving subclasses,
  32  * since it provides common code needed for handling a single child widget.
  33  *
  34  * Many GTK+ widgets are subclasses of #GtkBin, including #GtkWindow,
  35  * #GtkButton, #GtkFrame, #GtkHandleBox or #GtkScrolledWindow.
  36  */
  37
  38 #include "config.h"
  39 #include "gtkbin.h"
  40 #include "gtksizerequest.h"
  41 #include "gtkintl.h"
  42
  43
  44 struct _GtkBinPrivate
  45 {
  46   GtkWidget *child;
  47 };
  48
  49 static void gtk_bin_add         (GtkContainer   *container,
  50                                  GtkWidget      *widget);
  51 static void gtk_bin_remove      (GtkContainer   *container,
  52                                  GtkWidget      *widget);
  53 static void gtk_bin_forall      (GtkContainer   *container,
  54                                  gboolean       include_internals,
  55                                  GtkCallback     callback,
  56                                  gpointer        callback_data);
  57 static GType gtk_bin_child_type (GtkContainer   *container);
  58
  59 static void               gtk_bin_get_preferred_width             (GtkWidget           *widget,
  60                                                                    gint                *minimum_width,
  61                                                                    gint                *natural_width);
  62 static void               gtk_bin_get_preferred_height            (GtkWidget           *widget,
  63                                                                    gint                *minimum_height,
  64                                                                    gint                *natural_height);
  65 static void               gtk_bin_get_preferred_width_for_height  (GtkWidget           *widget,
  66                                                                    gint                 height,
  67                                                                    gint                *minimum_width,
  68                                                                    gint                *natural_width);
  69 static void               gtk_bin_get_preferred_height_for_width  (GtkWidget           *widget,
  70                                                                    gint                 width,
  71                                                                    gint                *minimum_height,
  72                                                                    gint                *natural_height);
  73 static void               gtk_bin_size_allocate                   (GtkWidget           *widget,
  74                                                                    GtkAllocation       *allocation);
  75
  76 G_DEFINE_ABSTRACT_TYPE (GtkBin, gtk_bin, GTK_TYPE_CONTAINER)
  77
  78 static void
  79 gtk_bin_class_init (GtkBinClass *class)
  80 {
  81   GtkWidgetClass *widget_class = (GtkWidgetClass*) class;
  82   GtkContainerClass *container_class = (GtkContainerClass*) class;
  83
  84   widget_class->get_preferred_width = gtk_bin_get_preferred_width;
  85   widget_class->get_preferred_height = gtk_bin_get_preferred_height;
  86   widget_class->get_preferred_width_for_height = gtk_bin_get_preferred_width_for_height;
  87   widget_class->get_preferred_height_for_width = gtk_bin_get_preferred_height_for_width;
  88   widget_class->size_allocate = gtk_bin_size_allocate;
  89
  90   container_class->add = gtk_bin_add;
  91   container_class->remove = gtk_bin_remove;
  92   container_class->forall = gtk_bin_forall;
  93   container_class->child_type = gtk_bin_child_type;
  94
  95   g_type_class_add_private (class, sizeof (GtkBinPrivate));
  96 }
  97
  98 static void
  99 gtk_bin_init (GtkBin *bin)
 100 {
 101   GtkBinPrivate *priv;
 102
 103   bin->priv = G_TYPE_INSTANCE_GET_PRIVATE (bin,
 104                                            GTK_TYPE_BIN,
 105                                            GtkBinPrivate);
 106   priv = bin->priv;
 107
 108   gtk_widget_set_has_window (GTK_WIDGET (bin), FALSE);
 109
 110   priv->child = NULL;
 111 }
 112
 113
 114 static GType
 115 gtk_bin_child_type (GtkContainer *container)
 116 {
 117   GtkBinPrivate *priv = GTK_BIN (container)->priv;
 118
 119   if (!priv->child)
 120     return GTK_TYPE_WIDGET;
 121   else
 122     return G_TYPE_NONE;
 123 }
 124
 125 static void
 126 gtk_bin_add (GtkContainer *container,
 127              GtkWidget    *child)
 128 {
 129   GtkBin *bin = GTK_BIN (container);
 130   GtkBinPrivate *priv = bin->priv;
 131
 132   if (priv->child != NULL)
 133     {
 134       g_warning ("Attempting to add a widget with type %s to a %s, "
 135                  "but as a GtkBin subclass a %s can only contain one widget at a time; "
 136                  "it already contains a widget of type %s",
 137                  g_type_name (G_OBJECT_TYPE (child)),
 138                  g_type_name (G_OBJECT_TYPE (bin)),
 139                  g_type_name (G_OBJECT_TYPE (bin)),
 140                  g_type_name (G_OBJECT_TYPE (priv->child)));
 141       return;
 142     }
 143
 144   gtk_widget_set_parent (child, GTK_WIDGET (bin));
 145   priv->child = child;
 146 }
 147
 148 static void
 149 gtk_bin_remove (GtkContainer *container,
 150                 GtkWidget    *child)
 151 {
 152   GtkBin *bin = GTK_BIN (container);
 153   GtkBinPrivate *priv = bin->priv;
 154   gboolean widget_was_visible;
 155
 156   g_return_if_fail (priv->child == child);
 157
 158   widget_was_visible = gtk_widget_get_visible (child);
 159
 160   gtk_widget_unparent (child);
 161   priv->child = NULL;
 162
 163   /* queue resize regardless of gtk_widget_get_visible (container),
 164    * since that's what is needed by toplevels, which derive from GtkBin.
 165    */
 166   if (widget_was_visible)
 167     gtk_widget_queue_resize (GTK_WIDGET (container));
 168 }
 169
 170 static void
 171 gtk_bin_forall (GtkContainer *container,
 172                 gboolean      include_internals,
 173                 GtkCallback   callback,
 174                 gpointer      callback_data)
 175 {
 176   GtkBin *bin = GTK_BIN (container);
 177   GtkBinPrivate *priv = bin->priv;
 178
 179   if (priv->child)
 180     (* callback) (priv->child, callback_data);
 181 }
 182
 183
 184 /* GtkBin widgets define the padding and borders independantly so
 185  * we cannot provide a generic get_size() for the same reason
 186  * we never implemented size_request() here.
 187  *
 188  * But for cases where the GtkBin class's padding is constant and
 189  * does not vary based on allocation (most cases), we can at least
 190  * deduce a common code path for the get_width_for_height()/get_height_for_width()
 191  * cases by using the delta of the base size requsts.
 192  */
 193 static void
 194 get_child_padding_delta (GtkBin *bin,
 195                          gint   *delta_h,
 196                          gint   *delta_v)
 197 {
 198   GtkBinPrivate *priv = bin->priv;
 199   gint hmin, vmin, hnat, vnat, child_hmin, child_vmin;
 200
 201   /* we can't use gtk_widget_get_preferred_width() wrapper
 202    * because we want our "original" request, not any external
 203    * adjustments from set_size_request() or whatever.  we have
 204    * to ask for natural also because NULL isn't allowed for the
 205    * direct vfuncs
 206    */
 207   GTK_WIDGET_GET_CLASS (bin)->get_preferred_width (GTK_WIDGET (bin), &hmin, &hnat);
 208   GTK_WIDGET_GET_CLASS (bin)->adjust_size_request (GTK_WIDGET (bin),
 209                                                    GTK_ORIENTATION_HORIZONTAL, &hmin, &hnat);
 210
 211   GTK_WIDGET_GET_CLASS (bin)->get_preferred_height (GTK_WIDGET (bin), &vmin, &vnat);
 212   GTK_WIDGET_GET_CLASS (bin)->adjust_size_request (GTK_WIDGET (bin),
 213                                                    GTK_ORIENTATION_VERTICAL, &vmin, &vnat);
 214
 215   gtk_widget_get_preferred_width (priv->child, &child_hmin, NULL);
 216   gtk_widget_get_preferred_height (priv->child, &child_vmin, NULL);
 217
 218   *delta_h = hmin - child_hmin;
 219   *delta_v = vmin - child_vmin;
 220 }
 221
 222 static void
 223 gtk_bin_get_preferred_width (GtkWidget *widget,
 224                              gint      *minimum_width,
 225                              gint      *natural_width)
 226 {
 227   GtkBin *bin = GTK_BIN (widget);
 228   GtkBinPrivate *priv = bin->priv;
 229
 230   if (priv->child)
 231     {
 232       gint child_min, child_nat;
 233       gtk_widget_get_preferred_width (priv->child,
 234                                       &child_min, &child_nat);
 235       *minimum_width = child_min;
 236       *natural_width = child_nat;
 237     }
 238 }
 239
 240 static void
 241 gtk_bin_get_preferred_height (GtkWidget *widget,
 242                               gint      *minimum_height,
 243                               gint      *natural_height)
 244 {
 245   GtkBin *bin = GTK_BIN (widget);
 246   GtkBinPrivate *priv = bin->priv;
 247
 248   if (priv->child)
 249     {
 250       gint child_min, child_nat;
 251       gtk_widget_get_preferred_height (priv->child,
 252                                        &child_min, &child_nat);
 253       *minimum_height = child_min;
 254       *natural_height = child_nat;
 255     }
 256 }
 257
 258 static void
 259 gtk_bin_get_preferred_width_for_height (GtkWidget *widget,
 260                                         gint       height,
 261                                         gint      *minimum_width,
 262                                         gint      *natural_width)
 263 {
 264   GtkBin *bin = GTK_BIN (widget);
 265   GtkBinPrivate *priv = bin->priv;
 266   gint    hdelta, vdelta, child_min, child_nat;
 267
 268   if (priv->child)
 269     {
 270       get_child_padding_delta (bin, &hdelta, &vdelta);
 271
 272       gtk_widget_get_preferred_width_for_height (priv->child,
 273                                                  height - vdelta,
 274                                                  &child_min, &child_nat);
 275
 276       if (minimum_width)
 277         *minimum_width = child_min + hdelta;
 278
 279       if (natural_width)
 280         *natural_width = child_nat + hdelta;
 281     }
 282   else
 283     GTK_WIDGET_GET_CLASS (widget)->get_preferred_width (widget, minimum_width, natural_width);
 284 }
 285
 286 static void
 287 gtk_bin_get_preferred_height_for_width  (GtkWidget *widget,
 288                                          gint       width,
 289                                          gint      *minimum_height,
 290                                          gint      *natural_height)
 291 {
 292   GtkBin *bin = GTK_BIN (widget);
 293   GtkBinPrivate *priv = bin->priv;
 294   gint    hdelta, vdelta, child_min, child_nat;
 295
 296   if (priv->child)
 297     {
 298       get_child_padding_delta (bin, &hdelta, &vdelta);
 299
 300       gtk_widget_get_preferred_height_for_width (priv->child,
 301                                                  width - hdelta,
 302                                                  &child_min, &child_nat);
 303
 304       if (minimum_height)
 305         *minimum_height = child_min + vdelta;
 306
 307       if (natural_height)
 308         *natural_height = child_nat + vdelta;
 309     }
 310   else
 311     GTK_WIDGET_GET_CLASS (widget)->get_preferred_height (widget, minimum_height, natural_height);
 312 }
 313
 314 static void
 315 gtk_bin_size_allocate (GtkWidget     *widget,
 316                        GtkAllocation *allocation)
 317 {
 318   GtkBin *bin = GTK_BIN (widget);
 319   GtkBinPrivate *priv = bin->priv;
 320
 321   gtk_widget_set_allocation (widget, allocation);
 322
 323   if (priv->child)
 324     gtk_widget_size_allocate (priv->child, allocation);
 325 }
 326
 327 /**
 328  * gtk_bin_get_child:
 329  * @bin: a #GtkBin
 330  *
 331  * Gets the child of the #GtkBin, or %NULL if the bin contains
 332  * no child widget. The returned widget does not have a reference
 333  * added, so you do not need to unref it.
 334  *
 335  * Return value: (transfer none): pointer to child of the #GtkBin
 336  **/
 337 GtkWidget*
 338 gtk_bin_get_child (GtkBin *bin)
 339 {
 340   g_return_val_if_fail (GTK_IS_BIN (bin), NULL);
 341
 342   return bin->priv->child;
 343 }
 344
 345 void
 346 _gtk_bin_set_child (GtkBin    *bin,
 347                     GtkWidget *widget)
 348 {
 349   bin->priv->child = widget;
 350 }